Nanomedicine is an emerging field that is expected to alter the landscape of oncology. In the past 20-30 years, efforts have been mainly devoted to the development of polymeric nanomedicine technology (micelles, nanoparticles, polymer-drug conjugates, and the like) that can be formulated by copolymer self-assembly, nanoprecipitation or conjugation, which can accumulate in tumors via Enhanced Permission and Retention (EPR), a passive targeting mechanism.
Although significant progress has been made, the conventional formulations usually afford drug delivery nanostructures with random and wide-ranging particle sizes. The size of drug delivery vehicles has been strongly correlated with their in vivo biodistribution, penetration in tumor tissue and intracellular trafficking. Particle size of a therapeutic nanoparticle, therefore, has a significant impact on antitumor efficacy.
Size control has been achieved recently with the use of top-down technology. However, it is still a significant obstacle to make large quantity of nanoparticles with controlled sizes, especially nanoparticles with diameters less than 100 nm, which size is favorable for tumor accumulation. Accordingly, what is needed are new nanoparticles that can be prepared on a large scale with controlled sizes.